Процес наномодифікації кераміки та прогнозування фізико-механічних властивостей нанокерамічних матеріалів

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dc.contributor.authorШилович, Ярослав Ігорович
dc.date.accessioned2021-12-07T09:54:53Z
dc.date.available2021-12-07T09:54:53Z
dc.date.issued2021
dc.description.abstractenThe dissertation concerns mainly the research of the process of nanomodification of ceramic materials during their manufacturing, in particular insertion of nanoparticles contained in a water-based suspension into the ceramic slip in process of its manufacture into ceramic mass. However, it also explores the process of nanomodified suspension as the nanoparticle agglomerates are dispersed with ultrasonic dispersion technology. Cavitation pressure adequate for dispersion of said nanoaglomerates is defined, which is crucial for further calibrating of dispersion equipment designed for nanoceramic material production. An analytical review of contemporary literature describing nanomodification of building materials, their methods fabrication, experimental study of the effect of nanomodification on properties of the obtained materials and numerical modeling of physical mechanical properties of nanomaterials has been conducted. The literary survey had shown the lack of conducted research and hence the need for further research into the introduction of nanocomposites into building materials, including ceramics, to explore the possibility of improved performance properties in these materials. One of the areas of improvement of the quality of composite materials, including building materials, is the application of nanotechnologies. Introduction of nanosystems in very small quantities (less than 0.5%) leads to an increase in mechanical and operational properties. Pre-process of nanomodification in carbon nanomaterials ceramics, prepared with for ceramic slip and ceramic glaze. Nanomaterial processing for nanomodification, preparation in DP “Ukrainian State Scientific-Preceding Carbonchemical Institute (UHIN)”. For the introduction into the slip, a water suspension was prepared with addition of mass of nanoparticles from 0.5 to 9 wt. %. To be added to the glaze, it was prepared with water a suspension with a mass of nanoparticles 5; 7; 9 wt %. Directly before introduction into the mass, the aqueous suspension was subjected to ultrasound dispersions for breaking up agglomerates of nanoparticles and their uniform distribution in the volume of liquid. The aqueous suspension was introduced into the liquid mass (slip and glaze) by mixing with a mechanical stirrer. From the received samples of ceramics were made for the study of their physical mechanical properties and samples of glazed coatings for research their hydrophobic properties. Nanomodified ceramics were studied by indicators: moisture content, linear shrinkage, porosity, mechanical flexural strength. The obtained results were compared with the values for the reference samples. The results showed that nanomodification affects the following properties: moisture content decreased by 1 – 4 %, linear shrinkage decreased by 0.6 – 4 %, porosity decreased by 1.5 times. Mechanical strength in bending increased by 25 – 36 %. Nanomodified glaze was applied to ceramic tiles and studied for its hydrophobic properties, namely the angle of wetting the surface of the glaze with water was experimentally investigated by static and dynamic drop method. It is determined that nanomodified on the glaze has better hydrophobic properties compared to the reference glaze: an increase in the contact angle between the water droplet and nanoglazed surface by 71.1 % and reducing the rolling angle of the drop at 68.5 %. According to the calculations and based on known data it was substantiated that ultrasonic effect during dispersion of nanoparticles in aqueous suspension is attributed to cavitation effects that occur when microbubbles collapse in the aqueous solution. The calculation of cavitation pulse and mechanical stress that occur when bubbles collapse in the range of changes in their radius (Rmax – R0) is proposed. As a result, a recommendation for the selection or practical application of dispersant of a certain power in the manufacture of a nano-containing suspension is developed. To model the processes of linear and nonlinear deformation nanotubes of different types using methods of molecular mechanics and molecular dynamics developed a special finite element (FE) on based on the moment scheme of finite elements of Professor Sakharov O.S. Covalent bonding forces between carbon atoms in a finite element are described on the basis of Morse potential. in order to predict the physical mechanical properties of nanomodified composites is finite the element is integrated into the APROKS system. For correct modeling of interaction of carbon atoms in the structure of the hexagonal shape of the "nanocell" two FE docking schemes have been implemented. The first scheme of the type "overlap" establishes docking by providing stitching of knots of two finite elements, joined by displacements. Another scheme carried out by transferring forces through a special hexagon FE - "atom". Approbation of the developed finite element is performed by comparing the results of numerical experiments with known ones numerical solutions, namely the study to determine reduced modulus of elasticity of nanotubes such as "armchair" and "zigzag" with various indicators of the chirality index, the discrepancy of results doesn’t exceed 5 % in comparison to the numerical solutions known from the literature, in which which beam FE with a circular cross section were used, from the standard libraries of finite elements of the ANSYS system. A multi-scale strength criterion is proposed for nanomodified brittle materials, which binds the processes of occurrence damage on a macro-, micro- and nanoscale. Criterion tested by comparing the numerical simulation data obtained on it based on data from field experiments, obtained well for agreement with experimental data not exceeding 2.9 % for samples made according to recipe 1 and 8.3 % - for samples made by recipe #2. The results of the research allow us to conclude that the developed method of estimating the strength of nanomodified ceramics can be used in assessing the strength of new ceramic products of various kinds appointment.uk
dc.description.abstractukДисертаційну роботу присвячено дослідженню процесів наномодифікації керамічних матеріалів, фізико-механічних властивостей отриманих наномодифікованих матеріалів та чисельному дослідженню властивостей наномодифікованих матеріалів. Отримано експериментальні зразки наномодифікованої вуглецевими наноматеріалами кераміки, виготовленої шляхом шлікерного лиття та керамічної глазурі. Для введення в шлікер виготовлено водяну суспензію з масовим вмістом наночастинок від 0,5 до 9 мас. %. Отримано результати експериментального дослідження фізико-механічних властивостей наномодифікованої кераміки, а саме вологовмісту, лінійної усадки, пористості, механічної міцності на вигинання, а також гідрофобних властивостей глазурованих покриттів. Обґрунтовано, що ультразвуковий вплив при диспергуванні наночастинок у водяній суспензії обумовлено кавітаційними ефектами, що виникають при схлопуванні мікробульбашок у водному розчині. Для практичного застосуванням розроблено рекомендацію щодо вибору диспергатора певної потужності при виготовленні нановмісної суспензії. Розроблено та численно реалізовано метод визначення параметрів міцності виробів із наноармованої кераміки. Введено поняття про коефіцієнт армування. Запропоновано багатомасштабний критерій міцності наномодифікованих крихких матеріалів.uk
dc.format.page26 с.uk
dc.identifier.citationШилович, Я. І. Процес наномодифікації кераміки та прогнозування фізико-механічних властивостей нанокерамічних матеріалів : автореф. дис. … канд. техн. наук. : 05.17.08 – процеси та обладнання хімічної технології / Шилович Ярослав Ігорович. – Київ, 2021. – 26 с.uk
dc.identifier.urihttps://ela.kpi.ua/handle/123456789/45459
dc.language.isoukuk
dc.publisherКПІ ім. Ігоря Сікорськогоuk
dc.publisher.placeКиївuk
dc.subjectкерамікаuk
dc.subjectглазурuk
dc.subjectшлікерuk
dc.subjectдиспергаціяuk
dc.subjectнанотрубкаuk
dc.subjectмежа міцностіuk
dc.subjectceramicsuk
dc.subjectglazeuk
dc.subjectslipuk
dc.subjectdispersionuk
dc.subjectnanotubeuk
dc.subjecttensile strengthuk
dc.subject.udc666.3.022.66+666.295.1:66-963uk
dc.titleПроцес наномодифікації кераміки та прогнозування фізико-механічних властивостей нанокерамічних матеріалівuk
dc.typeThesisuk

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